Implement generation of biome decorations to //regen <biome> and add option for a random seed to be used (#1819)

worldedit-bukkit/adapters/adapter-1_17_1/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_17_R1_2/regen/PaperweightRegen.java

@@ -11,7 +11,6 @@ import com.mojang.datafixers.util.Either;
 import com.mojang.serialization.Codec;
 import com.mojang.serialization.Lifecycle;
 import com.sk89q.worldedit.bukkit.adapter.Refraction;
-import com.sk89q.worldedit.bukkit.adapter.ext.fawe.PaperweightAdapter;
 import com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_17_R1_2.PaperweightGetBlocks;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.internal.util.LogManagerCompat;
@@ -38,6 +37,7 @@ import net.minecraft.world.level.LevelHeightAccessor;
 import net.minecraft.world.level.LevelSettings;
 import net.minecraft.world.level.biome.Biome;
 import net.minecraft.world.level.biome.BiomeSource;
+import net.minecraft.world.level.biome.FixedBiomeSource;
 import net.minecraft.world.level.biome.OverworldBiomeSource;
 import net.minecraft.world.level.chunk.ChunkAccess;
 import net.minecraft.world.level.chunk.ChunkGenerator;
@@ -67,6 +67,7 @@ import org.bukkit.Bukkit;
 import org.bukkit.craftbukkit.v1_17_R1.CraftServer;
 import org.bukkit.craftbukkit.v1_17_R1.CraftWorld;
 import org.bukkit.craftbukkit.v1_17_R1.generator.CustomChunkGenerator;
+import org.bukkit.generator.BiomeProvider;
 import org.bukkit.generator.BlockPopulator;
 
 import javax.annotation.Nullable;
@@ -213,6 +214,8 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         session = levelStorageSource.createAccess("faweregentempworld", levelStemResourceKey);
         PrimaryLevelData originalWorldData = originalServerWorld.serverLevelData;
 
+        BiomeProvider biomeProvider = getBiomeProvider();
+
         MinecraftServer server = originalServerWorld.getCraftServer().getServer();
         PrimaryLevelData levelProperties = (PrimaryLevelData) server.getWorldData();
 
@@ -246,7 +249,7 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
                 false,
                 environment,
                 generator,
-                originalBukkitWorld.getBiomeProvider()
+                biomeProvider
         ) {
             private final Biome singleBiome = options.hasBiomeType() ? BuiltinRegistries.BIOME.get(ResourceLocation.tryParse(
                     options
@@ -280,9 +283,16 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         } else if (originalChunkProvider.getGenerator() instanceof NoiseBasedChunkGenerator) {
             Supplier<NoiseGeneratorSettings> generatorSettingBaseSupplier = (Supplier<NoiseGeneratorSettings>) generatorSettingBaseSupplierField
                     .get(originalChunkProvider.getGenerator());
-            BiomeSource biomeSource = originalChunkProvider.getGenerator().getBiomeSource();
+            BiomeSource biomeSource;
-            if (biomeSource instanceof OverworldBiomeSource) {
+            if (options.hasBiomeType()) {
-                biomeSource = fastOverworldBiomeSource(biomeSource);
+                biomeSource = new FixedBiomeSource(BuiltinRegistries.BIOME.get(ResourceLocation.tryParse(options
+                        .getBiomeType()
+                        .getId())));
+            } else {
+                biomeSource = originalChunkProvider.getGenerator().getBiomeSource();
+                if (biomeSource instanceof OverworldBiomeSource) {
+                    biomeSource = fastOverworldBiomeSource(biomeSource);
+                }
             }
             chunkGenerator = new NoiseBasedChunkGenerator(biomeSource, seed, generatorSettingBaseSupplier);
         } else if (originalChunkProvider.getGenerator() instanceof CustomChunkGenerator) {

worldedit-bukkit/adapters/adapter-1_18_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_18_R2/regen/PaperweightRegen.java

@@ -17,6 +17,7 @@ import com.sk89q.worldedit.internal.util.LogManagerCompat;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.io.file.SafeFiles;
 import com.sk89q.worldedit.world.RegenOptions;
+import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import net.minecraft.core.Holder;
 import net.minecraft.core.Registry;
 import net.minecraft.data.BuiltinRegistries;
@@ -33,6 +34,7 @@ import net.minecraft.world.level.LevelHeightAccessor;
 import net.minecraft.world.level.LevelSettings;
 import net.minecraft.world.level.biome.Biome;
 import net.minecraft.world.level.biome.BiomeSource;
+import net.minecraft.world.level.biome.FixedBiomeSource;
 import net.minecraft.world.level.chunk.ChunkAccess;
 import net.minecraft.world.level.chunk.ChunkGenerator;
 import net.minecraft.world.level.chunk.ChunkStatus;
@@ -46,6 +48,7 @@ import net.minecraft.world.level.levelgen.NoiseGeneratorSettings;
 import net.minecraft.world.level.levelgen.WorldGenSettings;
 import net.minecraft.world.level.levelgen.blending.BlendingData;
 import net.minecraft.world.level.levelgen.flat.FlatLevelGeneratorSettings;
+import net.minecraft.world.level.levelgen.structure.placement.ConcentricRingsStructurePlacement;
 import net.minecraft.world.level.levelgen.structure.templatesystem.StructureManager;
 import net.minecraft.world.level.storage.LevelStorageSource;
 import net.minecraft.world.level.storage.PrimaryLevelData;
@@ -54,6 +57,7 @@ import org.bukkit.Bukkit;
 import org.bukkit.craftbukkit.v1_18_R2.CraftServer;
 import org.bukkit.craftbukkit.v1_18_R2.CraftWorld;
 import org.bukkit.craftbukkit.v1_18_R2.generator.CustomChunkGenerator;
+import org.bukkit.generator.BiomeProvider;
 import org.bukkit.generator.BlockPopulator;
 
 import javax.annotation.Nullable;
@@ -81,6 +85,8 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
     private static final Field generatorSettingBaseSupplierField;
     private static final Field delegateField;
     private static final Field chunkSourceField;
+    private static final Field ringPositionsField;
+    private static final Field hasGeneratedPositionsField;
 
     //list of chunk stati in correct order without FULL
     private static final Map<ChunkStatus, Concurrency> chunkStati = new LinkedHashMap<>();
@@ -139,6 +145,12 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
 
             chunkSourceField = ServerLevel.class.getDeclaredField(Refraction.pickName("chunkSource", "K"));
             chunkSourceField.setAccessible(true);
+
+            ringPositionsField = ChunkGenerator.class.getDeclaredField(Refraction.pickName("ringPositions", "i"));
+            ringPositionsField.setAccessible(true);
+
+            hasGeneratedPositionsField = ChunkGenerator.class.getDeclaredField(Refraction.pickName("hasGeneratedPositions", "j"));
+            hasGeneratedPositionsField.setAccessible(true);
         } catch (Exception e) {
             throw new RuntimeException(e);
         }
@@ -198,6 +210,8 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         session = levelStorageSource.createAccess("faweregentempworld", levelStemResourceKey);
         PrimaryLevelData originalWorldData = originalServerWorld.serverLevelData;
 
+        BiomeProvider biomeProvider = getBiomeProvider();
+
         MinecraftServer server = originalServerWorld.getCraftServer().getServer();
         PrimaryLevelData levelProperties = (PrimaryLevelData) server.getWorldData();
         WorldGenSettings originalOpts = levelProperties.worldGenSettings();
@@ -232,7 +246,7 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
                 false,
                 environment,
                 generator,
-                originalBukkitWorld.getBiomeProvider()
+                biomeProvider
         ) {
             private final Holder<Biome> singleBiome = options.hasBiomeType() ? BuiltinRegistries.BIOME.asHolderIdMap().byId(
                     WorldEditPlugin.getInstance().getBukkitImplAdapter().getInternalBiomeId(options.getBiomeType())
@@ -260,22 +274,30 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         }
 
         //generator
-        if (originalChunkProvider.getGenerator() instanceof FlatLevelSource flatLevelSource) {
+        ChunkGenerator originalGenerator = originalChunkProvider.getGenerator();
+        if (originalGenerator instanceof FlatLevelSource flatLevelSource) {
             FlatLevelGeneratorSettings generatorSettingFlat = flatLevelSource.settings();
-            chunkGenerator = new FlatLevelSource(originalChunkProvider.getGenerator().structureSets, generatorSettingFlat);
+            chunkGenerator = new FlatLevelSource(originalGenerator.structureSets, generatorSettingFlat);
-        } else if (originalChunkProvider.getGenerator() instanceof NoiseBasedChunkGenerator noiseBasedChunkGenerator) {
+        } else if (originalGenerator instanceof NoiseBasedChunkGenerator noiseBasedChunkGenerator) {
             Holder<NoiseGeneratorSettings> generatorSettingBaseSupplier =
                     (Holder<NoiseGeneratorSettings>) generatorSettingBaseSupplierField
-                            .get(originalChunkProvider.getGenerator());
+                            .get(originalGenerator);
-            BiomeSource biomeSource = originalChunkProvider.getGenerator().getBiomeSource();
+            BiomeSource biomeSource;
-            chunkGenerator = new NoiseBasedChunkGenerator(originalChunkProvider.getGenerator().structureSets, noiseBasedChunkGenerator.noises,
+            if (options.hasBiomeType()) {
+                biomeSource = new FixedBiomeSource(BuiltinRegistries.BIOME
+                        .asHolderIdMap()
+                        .byId(WorldEditPlugin.getInstance().getBukkitImplAdapter().getInternalBiomeId(options.getBiomeType())));
+            } else {
+                biomeSource = originalGenerator.getBiomeSource();
+            }
+            chunkGenerator = new NoiseBasedChunkGenerator(originalGenerator.structureSets, noiseBasedChunkGenerator.noises,
                     biomeSource, seed,
                     generatorSettingBaseSupplier
             );
-        } else if (originalChunkProvider.getGenerator() instanceof CustomChunkGenerator customChunkGenerator) {
+        } else if (originalGenerator instanceof CustomChunkGenerator customChunkGenerator) {
             chunkGenerator = customChunkGenerator.delegate;
         } else {
-            LOGGER.error("Unsupported generator type {}", originalChunkProvider.getGenerator().getClass().getName());
+            LOGGER.error("Unsupported generator type {}", originalGenerator.getClass().getName());
             return false;
         }
         if (generator != null) {
@@ -283,6 +305,20 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
             generateConcurrent = generator.isParallelCapable();
         }
 
+        if (seed == originalOpts.seed() && !options.hasBiomeType()) {
+            // Optimisation for needless ring position calculation when the seed and biome is the same.
+            boolean hasGeneratedPositions = hasGeneratedPositionsField.getBoolean(originalGenerator);
+            if (hasGeneratedPositions) {
+                Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>> ringPositions =
+                        (Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>>) ringPositionsField.get(
+                                originalGenerator);
+                Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>> copy = new Object2ObjectArrayMap<>(ringPositions);
+                ringPositionsField.set(chunkGenerator, copy);
+                hasGeneratedPositionsField.setBoolean(chunkGenerator, true);
+            }
+        }
+
+
         chunkGenerator.conf = originalServerWorld.spigotConfig;
         freshChunkProvider = new ServerChunkCache(
                 freshWorld,

worldedit-bukkit/adapters/adapter-1_19/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R1/regen/PaperweightRegen.java

@@ -17,6 +17,7 @@ import com.sk89q.worldedit.internal.util.LogManagerCompat;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.io.file.SafeFiles;
 import com.sk89q.worldedit.world.RegenOptions;
+import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import net.minecraft.core.Holder;
 import net.minecraft.core.Registry;
 import net.minecraft.data.BuiltinRegistries;
@@ -36,6 +37,7 @@ import net.minecraft.world.level.LevelHeightAccessor;
 import net.minecraft.world.level.LevelSettings;
 import net.minecraft.world.level.biome.Biome;
 import net.minecraft.world.level.biome.BiomeSource;
+import net.minecraft.world.level.biome.FixedBiomeSource;
 import net.minecraft.world.level.chunk.ChunkAccess;
 import net.minecraft.world.level.chunk.ChunkGenerator;
 import net.minecraft.world.level.chunk.ChunkStatus;
@@ -49,6 +51,7 @@ import net.minecraft.world.level.levelgen.NoiseGeneratorSettings;
 import net.minecraft.world.level.levelgen.WorldGenSettings;
 import net.minecraft.world.level.levelgen.blending.BlendingData;
 import net.minecraft.world.level.levelgen.flat.FlatLevelGeneratorSettings;
+import net.minecraft.world.level.levelgen.structure.placement.ConcentricRingsStructurePlacement;
 import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
 import net.minecraft.world.level.storage.LevelStorageSource;
 import net.minecraft.world.level.storage.PrimaryLevelData;
@@ -57,6 +60,7 @@ import org.bukkit.Bukkit;
 import org.bukkit.craftbukkit.v1_19_R1.CraftServer;
 import org.bukkit.craftbukkit.v1_19_R1.CraftWorld;
 import org.bukkit.craftbukkit.v1_19_R1.generator.CustomChunkGenerator;
+import org.bukkit.generator.BiomeProvider;
 import org.bukkit.generator.BlockPopulator;
 
 import javax.annotation.Nullable;
@@ -84,6 +88,8 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
     private static final Field generatorSettingBaseSupplierField;
     private static final Field delegateField;
     private static final Field chunkSourceField;
+    private static final Field ringPositionsField;
+    private static final Field hasGeneratedPositionsField;
 
     //list of chunk stati in correct order without FULL
     private static final Map<ChunkStatus, Concurrency> chunkStati = new LinkedHashMap<>();
@@ -142,6 +148,12 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
 
             chunkSourceField = ServerLevel.class.getDeclaredField(Refraction.pickName("chunkSource", "L"));
             chunkSourceField.setAccessible(true);
+
+            ringPositionsField = ChunkGenerator.class.getDeclaredField(Refraction.pickName("ringPositions", "i"));
+            ringPositionsField.setAccessible(true);
+
+            hasGeneratedPositionsField = ChunkGenerator.class.getDeclaredField(Refraction.pickName("hasGeneratedPositions", "j"));
+            hasGeneratedPositionsField.setAccessible(true);
         } catch (Exception e) {
             throw new RuntimeException(e);
         }
@@ -218,6 +230,8 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         );
         PrimaryLevelData newWorldData = new PrimaryLevelData(newWorldSettings, newOpts, Lifecycle.stable());
 
+        BiomeProvider biomeProvider = getBiomeProvider();
+
         //init world
         freshWorld = Fawe.instance().getQueueHandler().sync((Supplier<ServerLevel>) () -> new ServerLevel(
                 server,
@@ -233,7 +247,7 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
                 false,
                 environment,
                 generator,
-                originalBukkitWorld.getBiomeProvider()
+                biomeProvider
         ) {
             private final Holder<Biome> singleBiome = options.hasBiomeType() ? BuiltinRegistries.BIOME.asHolderIdMap().byId(
                     WorldEditPlugin.getInstance().getBukkitImplAdapter().getInternalBiomeId(options.getBiomeType())
@@ -260,27 +274,30 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
             paperConfigField.set(freshWorld, originalServerWorld.paperConfig());
         }
 
-        //generator
+        ChunkGenerator originalGenerator = originalChunkProvider.getGenerator();
-        // TODO figure out if this is needed. We can probably use
+        if (originalGenerator instanceof FlatLevelSource flatLevelSource) {
-        //  chunkGenerator = newOpts.dimensions().getOrThrow(levelStemResourceKey).generator();
-        //  instead.
-        if (originalChunkProvider.getGenerator() instanceof FlatLevelSource flatLevelSource) {
             FlatLevelGeneratorSettings generatorSettingFlat = flatLevelSource.settings();
-            chunkGenerator = new FlatLevelSource(originalChunkProvider.getGenerator().structureSets, generatorSettingFlat);
+            chunkGenerator = new FlatLevelSource(originalGenerator.structureSets, generatorSettingFlat);
-        } else if (originalChunkProvider.getGenerator() instanceof NoiseBasedChunkGenerator noiseBasedChunkGenerator) {
+        } else if (originalGenerator instanceof NoiseBasedChunkGenerator noiseBasedChunkGenerator) {
-            Holder<NoiseGeneratorSettings> generatorSettingBaseSupplier =
+            Holder<NoiseGeneratorSettings> generatorSettingBaseSupplier = (Holder<NoiseGeneratorSettings>) generatorSettingBaseSupplierField.get(
-                    (Holder<NoiseGeneratorSettings>) generatorSettingBaseSupplierField
+                    originalGenerator);
-                            .get(originalChunkProvider.getGenerator());
+            BiomeSource biomeSource;
-            BiomeSource biomeSource = originalChunkProvider.getGenerator().getBiomeSource();
+            if (options.hasBiomeType()) {
-            chunkGenerator = new NoiseBasedChunkGenerator(originalChunkProvider.getGenerator().structureSets,
+                biomeSource = new FixedBiomeSource(BuiltinRegistries.BIOME
+                        .asHolderIdMap()
+                        .byId(WorldEditPlugin.getInstance().getBukkitImplAdapter().getInternalBiomeId(options.getBiomeType())));
+            } else {
+                biomeSource = originalGenerator.getBiomeSource();
+            }
+            chunkGenerator = new NoiseBasedChunkGenerator(originalGenerator.structureSets,
                     noiseBasedChunkGenerator.noises,
                     biomeSource,
                     generatorSettingBaseSupplier
             );
-        } else if (originalChunkProvider.getGenerator() instanceof CustomChunkGenerator customChunkGenerator) {
+        } else if (originalGenerator instanceof CustomChunkGenerator customChunkGenerator) {
             chunkGenerator = customChunkGenerator.delegate;
         } else {
-            LOGGER.error("Unsupported generator type {}", originalChunkProvider.getGenerator().getClass().getName());
+            LOGGER.error("Unsupported generator type {}", originalGenerator.getClass().getName());
             return false;
         }
         if (generator != null) {
@@ -289,6 +306,19 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         }
         chunkGenerator.conf = freshWorld.spigotConfig;
 
+        if (seed == originalOpts.seed() && !options.hasBiomeType()) {
+            // Optimisation for needless ring position calculation when the seed and biome is the same.
+            boolean hasGeneratedPositions = hasGeneratedPositionsField.getBoolean(originalGenerator);
+            if (hasGeneratedPositions) {
+                Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>> ringPositions =
+                        (Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>>) ringPositionsField.get(
+                                originalGenerator);
+                Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>> copy = new Object2ObjectArrayMap<>(ringPositions);
+                ringPositionsField.set(chunkGenerator, copy);
+                hasGeneratedPositionsField.setBoolean(chunkGenerator, true);
+            }
+        }
+
         freshChunkProvider = new ServerChunkCache(
                 freshWorld,
                 session,
@@ -529,6 +559,7 @@ public class PaperweightRegen extends Regenerator<ChunkAccess, ProtoChunk, Level
         public CompletableFuture<ChunkAccess> lightChunk(final ChunkAccess chunk, final boolean excludeBlocks) {
             return CompletableFuture.completedFuture(chunk);
         }
+
     }
 
 }

worldedit-bukkit/src/main/java/com/fastasyncworldedit/bukkit/adapter/Regenerator.java

@@ -7,6 +7,7 @@ import com.fastasyncworldedit.core.queue.implementation.SingleThreadQueueExtent;
 import com.fastasyncworldedit.core.util.MathMan;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.bukkit.BukkitAdapter;
 import com.sk89q.worldedit.bukkit.BukkitWorld;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.function.pattern.Pattern;
@@ -22,10 +23,14 @@ import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
 import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
 import org.apache.logging.log4j.Logger;
+import org.bukkit.World;
+import org.bukkit.generator.BiomeProvider;
 import org.bukkit.generator.BlockPopulator;
+import org.bukkit.generator.WorldInfo;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
@@ -521,6 +526,13 @@ public abstract class Regenerator<IChunkAccess, ProtoChunk extends IChunkAccess,
         return tasks;
     }
 
+    protected BiomeProvider getBiomeProvider() {
+        if (options.hasBiomeType()) {
+            return new SingleBiomeProvider();
+        }
+        return originalBukkitWorld.getBiomeProvider();
+    }
+
     //classes
 
     public enum Concurrency {
@@ -624,4 +636,20 @@ public abstract class Regenerator<IChunkAccess, ProtoChunk extends IChunkAccess,
 
     }
 
+    public class SingleBiomeProvider extends BiomeProvider {
+
+        private final org.bukkit.block.Biome biome = BukkitAdapter.adapt(options.getBiomeType());
+
+        @Override
+        public org.bukkit.block.Biome getBiome(final WorldInfo worldInfo, final int x, final int y, final int z) {
+            return biome;
+        }
+
+        @Override
+        public List<org.bukkit.block.Biome> getBiomes(final WorldInfo worldInfo) {
+            return Collections.singletonList(biome);
+        }
+
+    }
+
 }

worldedit-core/src/main/java/com/sk89q/worldedit/command/RegionCommands.java

@@ -79,6 +79,7 @@ import org.enginehub.piston.annotation.param.Switch;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
 
 import static com.sk89q.worldedit.command.util.Logging.LogMode.ALL;
 import static com.sk89q.worldedit.command.util.Logging.LogMode.ORIENTATION_REGION;
@@ -691,6 +692,8 @@ public class RegionCommands {
                     Long seed,
             @Switch(name = 'b', desc = "Regenerate biomes as well")
                     boolean regenBiomes,
+            @Switch(name = 'r', desc = "If the seed should be randomized")
+                    boolean randomSeed,
             @Arg(desc = "Biome to apply for this regeneration (only works in overworld)", def = "")
                     BiomeType biomeType
     ) throws WorldEditException {
@@ -703,7 +706,7 @@ public class RegionCommands {
             actor.print(Caption.of("fawe.regen.time"));
             //FAWE end
             RegenOptions options = RegenOptions.builder()
-                    .seed(seed)
+                    .seed(!randomSeed ? seed : new Long(ThreadLocalRandom.current().nextLong()))
                     .regenBiomes(regenBiomes)
                     .biomeType(biomeType)
                     .build();